1. Field on Invention
The present invention relates to a winch for elevating at a plant, in particular for cranes, cable-operated excavators, and similar construction machinery, comprising a hoisting drum, an electric motor for the drive of the hoisting drum which is received in the interior of the hoisting drum as well as power and/or control electronics for the electric motor comprising at least one frequency inverter and/or frequency converter.
2. Description of the Prior Art
Hoisting winches driven by electric motors are generally known in which the transmission and the motor are arranged outside the winch drum. There are equally hoisting winches in which a planetary transmission is positioned inside the winch drum via which the winch drum is driven by an outwardly positioned motor, cf. DE 19 11 195 U1. Hoisting winches are furthermore known in which in addition to the integrated planetary transmission the electric motor is likewise located inside the hoisting winch drum, cf. DE 197 52 003 C2, which also wants to achieve a compact construction for winches for high load demands in that an asynchronous motor is used with a positively actuated liquid cooling which covers both the stator and the rotor serially. The control electronics for the electric motor are in this respect received in a switch cabinet which is integrated into the winch support and fits snugly between two hoisting drums journaled at the winch support.
The control of the described drive motors centrally from a switch cabinet, however, requires long electric cables. The cabling effort in this respect, in particular from the inverter to the motor, is substantial. Interference emissions arise due to long lines which have a negative effect with respect to the electromagnetic compatibility. Long motor feed lines can equally result in reflections and thereby to voltage overshoots which can substantially restrict the service life of the frequency inverter and motor.
Alternatively to this, attempts have already been made to use inverters integrated in the motor with non-installed electric motors arranged outside the hoisting drum. The latter is, however, restricted to comparatively small powers.